Second messenger systems and psychoactive drug action: Focus on the phosphoinositide system and lithium

Most models of psychotropic drug action have emphasized effects on the release or uptake of neurotransmitters as well as interactions with receptors. Stimulation of neurotransmitter receptors triggers a complex array of electrical and biochemical actions. Recent experimental advances have greatly clarified the second messenger systems underlying neurotransmitter actions, suggesting novel sites of action for psychotropic agents. The authors emphasize the phosphoinositide system and the implications of its involvement for the therapeutic actions of lithium.